1. Field of the Invention
The present invention relates to an engine control method and apparatus. More specifically, the present invention relates to an engine control method and apparatus in which fuel injection is controlled using an intake manifold pressure value.
2. Description of Background Art
In the background art, in an engine fuel injection control system, a control method that is so-called a speed density method for calculating a basic amount of fuel injection on the basis of a negative pressure in an intake manifold (hereinafter referred to as “manifold pressure”) and the engine revolution is known. A manifold pressure sensor is used for detecting the manifold pressure. In general, in order to maintain a normal system operation, a diagnostic apparatus for detecting a failure of the manifold pressure sensor is employed. For example, Japanese Patent Application Laid-Open No. 2003-307152 discloses an apparatus for determining an output signal from a sensor for sensing the intake manifold is within a preset range.